Prefabricated metal chimney



Feb. 23, 1965 A. KINKEAD ETAL PREFABRICATED METAL CHIMNEY 2 Sheets-Sheet 1 Filed March 1, 1962 INVENTORS. ALAN K/NKEAD RICHARD L. S

TONE

1965 A. KINKEAD ETAL PREFABRICATED METAL CHIMNEY 2 Sheets-Sheet 2 Filed March 1,

INVENTORS. ALAN KINKEAD RICHARD L. STONE United States Patent 3,170,544 PREFABRICATED METAL CHIMNEY Alan Kinlread and Richard L. Stone, Palo Alto, Caiif., assignors to William Waliace Corporation, Belmont, Calili, a corporation of Delaware Filed Mar. 1, 1962, Ser. No. 176,654 8 Claims. (Cl. 189--27) This invention relates to improvements in prefabricated metal chimneys of the type that can be manufactured in separate sections and later connected together on the job site.

Prefabricated metal chimneys offer certain inherent advantages, one important advantage being that they can .be used with all types of fuel and with all types of fuel burning home appliances. In general, such metal chimneys are double walled structures prefabricated in separate sections having a male and a female coupler end so that they are. connectable to other sections of a similar construction to form the completedchimney of the desired size at a particular v location. They thus eliminate the need for the old conventional masonry type :chimneys that are not only time-consuming and expensive tolconstruct, but also ineflicient in their operation.

A'primary object ofthe present invention is to provide an improved prefabricated metal chimney construction that overcomes some of the structural and operational problems of prior art chimney devices and which provides increased performance characterisitcs.

Qne serious problem with pref bricated metal chimneys prior to the present invention was that of compensating for the expansion of .the inner wall member which normally attains a much higher temperature than the outer wall member to which it is attached. In chimney designs heretofore utilized the. inner wall was restricted at both ends by its 'connection to the outer wall so when the inner wall expanded due to its higher temperature it caused a distortion of the male and female coupling members at the ends of the chimney section. This distortion reduced the annular air passages between adjoining sections which are important in eliminating the transfer 'of heat axially along the chimney and in dissipating heat therefrom. Also, in prior art double-walled metal chimney constructions, the expansion of the inner wall created the familiar and annoying oil can expansion noises that are usually characteristic of heated sheet metal conduits. .The present invention eliminates this effect and solves the entire inner wall expansion problem by means of a novelarrangement of elements wherein the inner wall is well supported but free to move'relative to the. outer wall so that its expansion does not affect the invention eliminates the problems of .the screw-type connection heretofore used and provides instead a novel 1 coupling construction that enables the prefabricatedmetal' pipe sections to' be joined together in perfect alignment V by an axial movement only of the pipe sections; Also,

means are provided to'assure a uniform annular space between ad oining sections an'd a novel locking means provides a positive snap-on lock between sectionsas they are moved togetheraxially. Yet, the sectionscan be disassembled easily, if desiredby a relatively small rotational movement between the sections.

Another advantage of the novel double walled chimney construction afforded by the present inventionis that it provides for the escape of moisture from Within the space between the inner wall and the outer wall. Without this feature any moisture vapor that might be trapped in the insulation material between the inner and outer wall members could not otherwise be released.

Still another object of the present invention is to provide a novel prefabricated metal chimney construction that enables the space between the inner and outer walls of the chimney section to be conveniently filled with insulating material. This is. an important factor because in order for the insulation material to be efiect-ive it;must be compacted under a substantial pressure. #111115, at

, least one coupler end must be able to withstand increased stresses during the filling process while the other coupler end must be readily installable and strong in order to retain the insulation material after-it has been inserted. 7

Other objects, advantages and features of the present invention will become apparent from the following description presented in accordance with 35 USC 112.

In the drawings: a 1 FIG. 1 is a view in elevation of a prefabricated chimney embodying the principles of the present invention as it appears in a typical installation;

- FIG, 2 is an enlarged view in elevation and in section showing a connected pair of chimney sections according to the invention;

FIG. 3 is a slightly reduced bottom'en d view of the chimney section of FIG. 2, taken along the line 3-3 and showing the female end of a chimney section according to the invention;

FIG. 4 is a slightly reduced top plan view of the male end ofa chimney section shown in FIG. 2;

FIG. 5 is a greatly enlarged fragmentary view in section showing in detail the male and female couplers of for a prefabricated chimneylh comprised of a plurality of connected chimney pipe sections '11, embodying the principles'of the invention. The sections 11 are constructed in a novel manner'soithat they can be conveniently and rapidly joined together to constitute the main height of the chimney. The base 'of the chimney 10 may be supported by a suitable chimney-support bucket assembly 12,"and at its upperend, the chimney it) may be equipped with a prefabricated housing 13. Such a housing is described in detail in our application Serial No. 98,928, filed March 28, 1961'. 1hr: bucket assembly 12 and the housing 13 are shown as being typical accessories for prefabricated metal. chimneys but neither is intended to'limit thescope of the present invention. I

The prefabricated chimney sections 11 have a novel double wall construction'providing an annularv space 14 for retaining ayhighternperature insulating fill l5. Insulating material such'as' a mineral fiberv like rock. wool canbe used and it mustbe packed tightly to prevent anydraft through the space 14. A novel and particularly effective insulation material for use in prefabrication fa'tented Feb. 23,}955

the inner diameter of the inner pipe 16, which is theflue passage, is inches and the outerdiameter of theiouter pipe 17 is 14 inches. The annularspace 14 which is filled with the insulating material 15 isthus approximately two 1 inches thick.

At the top ofeach-chimney'section 11 is a male cou .pler 18 and at the bottom of each section is a female coupler 1 The main elementformingthe male cou- 'pler 18 is an annular metal cup 20, :and a similar cup 21 is the main elementof the female gcoupler 19 As FIG. 2 shows,-the cup 21fissubstantially wider and deeper than the-cup-20,, and whenltwo adjacent sections .11 arev coupledtogether an annular air space 22 is formed'between the cups a and 21.

1 As shown in detail minds, the male cup20 has a topplate portion 23, an inner rim 24, and a tapered but nearly cylindrical outer connecting wall 25. A' plurality of'circumferentially spaced apart tabs 26 extend outward- 1y,'e.g. 30, and adjoiningchimneysections '11 together. Though the ends of the tabs 26lie essentially in a plane that passes through'the outer Wall perpendicular. to

' the insulation material 15. A clearance 51 ismaintained the pipe axis, they are also preferably inclined slightly- (ezgglOf) on the wall 25 in line with a right hand helix 7 pattern.

The inner pipe 16 is stepped out at a shoulder-27 (see FIG; 5) to provide a -wider-diameter portion'yZS that is; wider by an amount somewhat greater than thefthickness of the inner pipe 16. The portion 28 leads to another outstepped' shoulder 29 forminglan outer end portion 30' which fits the inner rim 24; of the male cup 20.. The inner rim '24 of the male cup me mber 20. is rigidlyattached to the outer end portion 30 of the inner wall 16 1 a}, v 'f The outer rim'of the: female 011 321 is connected to the lower end of the outer pipe '17 by a curled end connection 46.. Near its-lower end, the outer pipe 17 extends inwardly to form an annular groove .47 and'directly be low the groove 47 it extends outwardly to form ashoulder 48. Then it curls. inwardly to form a curled back end portion 49. The lower end portion 5110f the outerarirn 42 0f the female cup 21is formed ,tolie adjacent toand inside the annular shoulder 48, and the curled back end portion 49, thereby securing the female cup 21tothe outer wall 17 at this curled back joint 46;

The inner rim 41 of the female cup 21 is not con:

' nected to the inner wall16 but terminates closely adjacent to it, thereby closing the. annular space..14 at the lower female coupler end 19 'of the section 11 and retaining between'the inner rim 41and. the. inner wall 16 .so' that it is free toimove axially during expansion andcontrac tion. As shown .in FIG. 5,'when theIinnerwall 116pxpands, it is free to move axially along the out'steppedportion 28 above the. shoulder27 'of an adjoining chimney section 11 so that .a smooth uniform diameter -of}the chimney'l tl can beimaintained at the 'joints between see tions.=

The aforesaid novel arrangement of elements forming the pipe sections 11 solves important problems. and .pro-v vides several advantages over double" walled 'chimney structures heretofore devised. The inner .Wallfl being free at one end .can,expand' and contract'without affect;

ing the male or female couplers 18 and 19. Calculations indicate that expansion ,of about inch'per lineal foot is neededto allow for axial expansion of the inner pipe. With its lower end free to expand in'thislmanner there is V 'notendency for. the inner wall 16 to push upwardag ainst .by means ofa'series of spot welds-31 or rivet'fastenings.

spaced apart circumferentially along the innerrirn'24.

Before installation (see FIG. 8) the male cuplilhas a flat radial flange 32 and-the. outer rim portion 33 of this flange '32 is curled over duringmanufacture of the section 11.to'- join it to the outer wall-17;by means of a Pittsburgh joint 34. Theouter wall 17 extends downward from the. inside of the joint 34 for-a short distanceandthen extends radially outward at a shoulder- 35 thereby the. male'cup 20; This free floating arrangementforlthe inner pipewall eliminates any distortion of the. chimney 1% at its end couplers 18 0r 19 'or any need for the: .cou-p pling joint to flex duringbeatings The end couplers can thus be made stronger and more-rigid. Moreover, .by this novel arrangement, which allows the inner wall .16. to

move freely during expansiomthe presentinvention also eliminates the familiarv noisy oil can effects. that. heretofore plaguedzprefabricated metal'chirnneys,

Another important featureg'of the present invention is the couplingaction provided by the I outwardly circumferentially spacedtabs 26 cm the male coupler 20 which forming an annular slot'36 just below the joint '34. It

is apparent, I therefore, that the male cup 20 is. rigidly attached-Ito both the inner pipe 16 andthe outer pipe 17.

The. female cup 21 has acentral annular plate portion 40,41 down turned inner rim 41, and a downwardly extending outer rirn'42; -The outer. rim 42 is tapered slight ly, though nearly cylindrical, and has a plurality oficir cumferentially spaced tab members lfiithat. are-similar to and'whichtcooperate with the tabs 26 on the male cooperate with inwardlyv and upwardly extending tabs 43 on the female'coupler 21 to lock adjoining pipe sections '11 together. The'tabs 26 on the male coupler-211 may be formed'easily by providing circumferentially spaced apart U-shaped cuts in theouter wall 25 which are then bent-outwardly. As formed the tabs 26Eare-thus resilientlyyieldable. When apair of adj'oining-pipe sections coupler 18 to lockthe couplers 18 and 19 together; "The tabmemhers 43"extend.inwardly and upwardly from the outer rim .421and', as shownin FIGSQS and 7, they are substantially shorter in length than the tab members 26. Also,'.the tabs 43 lie in a plane perpendicul-ar.to the axis 'ofthe section 11,'and they arepreferably inclined ina i helix pattern similar to that of the tabs'26. As shown.

in FIG. 5, when the. male coupler 18 is axially seated in' p the. female coupler19, the tabs 26 of the male couplerv overlap and extend above the tab'sf laof the female. cou-' pler. .:To provide a means forlimi-ting th'eamount 'ofinserticnl of 'themalecouplr 18, in the femalecouplenw,

"a series' of radially extending depressions'45Y are formed. f andspaced apart cireumferentially" in an annular-plate portion 4130f the. female cup..21; v The depressions-:45

are 'of equalldepth and they serve to maintain the 'unia formannula'rfspace 22-between eachpair of adjacent sec-' 1 tions-11' that-is essential to'the dissipation of heat fromthe'chirnney 10.; Y t a 11 are connected, the male coupler. 1S. isrner'ely" moved axially into the female coupler1 until'the male cup 21 abuts against. the circtunferentially spaced :apart depressions or-blisters 45.011 thetinside of the female cup -21. At

7 this point, outwardly and inwardly. extending tabs 26 and43 of the male and female couplers-18 and'19barely overlap ,(seeYFlG. 5). If the tabs 26 and 43 are axially aligned when the two pipe sections 11 are engaged, they will initially been against each other and yield. inwardly .asthe sections are moved together, and as the top plate 23 of .themale cup 20 engages the spacing blistersf45, ,they willithen snap into the overlapping lockedfiposition.

Iftheltabs' Zd and .43 do not. happen to be aligned when the sectionsare axially. moved together, a small twist of the adjoining section :after the male coupler .118 is fully "inserted, :of'not rnore'than lidegreesewillrnoye them" into the; overlapping locking position showhdn FIG, 5. I 1

7 Although, itis generally not required-for most installations of theychimney 19, in'some instances an additionalstrengthening means may be provided by a band 53'havin'g achannel shaped cross section inaybe (extended around Leach joint; The flanges of. ,the 1,band extend" into .the

w ll

groove 47 above the curled end connection 46 of the female coupler 19 and into the groove 36 below the joint 34 on the male coupler 18 on adjoining sections 11. The ends of the band 53 are then drawn together in the well known manner by a bolt and nut connected through a pair of end flanges. Such an extra strengthening means would be desirable where the chimney is to be suspended, thus receiving more support from above than below.

When the chimney sections 11 are connected, their outer walls shed moisture and no Water can flow from outside into the inner pipe 16 or even get in between the couplers 18 and 19. The snugness of the inner pipe section 16 in the section 11 assures retention of all the flue gases inside the pipe 16.

The locking tabs 26 and 43 are not large enough to allow any of the installation material to escape from the space 14 between the inner and outer pipe sections 16 and 1'7, and actually they provide a ventilating means for releasing any moisture trapped in the insulation material.

From the foregoing, it is apparent that the present invention comprises a highly improved prefabricated chimney structure that provides new and unobvious results both in versatility and performance.

To those skilled in the art to which this invention relates, many changes in construction and widely diiiering embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

We claim:

1. A prefabricated double walled chimney section adapted to be coupled to a similar section to form a chimney column, said section comprising:

(a) an inner pipe;

(b) an outer pipe;

(0) insulation between said pipes;

(d) a male coupler on the upper end, and a female coupler on the lower end of said section, said couplers comprising- (e) annular radial plates with inner and outer generally axially extending flanges connected to said inner and outer pipes for retaining the spacing between them;

(f) said inner and outer flanges of said male coupler being rigidly connected to the upper ends of said inner and outer pipes, respectively;

(g) said outer pipe being rigidly connected to said female coupler outer flange at its lower end, and said inner pipe extending closely adjacent near its lower end to said female coupler inner flange and being movable relative thereto, said inner pipes of succeeding sectionsextending down into the inner pipe of the next lower section and below said plate;

(It) means for spacing said plates of adjacent couplers apart by a predetermined amount to provide a fixed annular air spaced between adjoining sections;

(1') and means on saidmale and female couplers for axially locking said section to an adjoining like section.

2; The device as described in claim 1 wherein said means for spacing said plates apartcomprises a plurality of circumferentially spaced apart depressions in said radial plate of said female coupler.

. 3. The device as described in claim 2 wherein said male coupler, and a plurality of tabs extending inwardly and upwardly from the outer flange of said female coupler, said tabs being resiliently yieldable when engaged during the axial connection of adjacent pipe sections and are so spaced axially on said couplers so that they can snap back into an overlapping locking position when said male coupler is abutted against said depression in an adjoining like chimney section.

4. The device as described in claim 3 wherein said tabs are inclined a predetermined amount with a plane perpendicular to the axis of said chimney section.

5. The device as described in claim 4 wherein said tabs are aligned along helical path with respect to the axis of said section and wherein said tabs on said male coupler are longer than the tabs on said female coupler.

6. A prefabricated double walled chimney section adapted to be coupled to a similar section to form a chimney column, said section comprising:

(a) an inner pipe;

(b) an outer pipe;

(0) insulation between said pipes;

(d) a male coupler on the upper end, and a female coupler on the lower end of said section, said couplers comprising (e) annular'radial plates'with inner and outer generally axially extending flanges connected to said inner and outer pipes for retaining the spacing between them;

(f) said inner flange of said male coupler overlapping and rigidly fastened to an outstepped upper end portion of said inner pipe and said outer flange of said male coupler being rigidly connected by means of a Pittsburgh joint to the upper end of said outer pipes, respectively;

(g) said outer pipe being rigidly connected by means of a curled around joint to said outer flange of said female coupler at its lower end, and said inner pipe extending closely adjacent near its lower end to and movable relative said inner flange of said female coupler, said inner pipes of succeeding sections extending down into the inner pipe of the next lower section and below said plate;

(h) means on said radial plates for spacing the plates of adjacent couplers apart to provide a fixed annular air space between adjoining sections;

' (i) and means on said male and female couplers for axially loclring said adjoining sectionstogether.

7. The device as described in claim 6 wherein said means for spacing the adjacent plates of adjoining secmeans for locking said sections together comprises a plurality of circumferentially spaced apart tabs extending downwardly and outwardly from said outer flange of said male coupler, and a plurality of tabs extending inwardly and upwardly from the outer flange of said female coupler, said tabs being resiliently yieldable when engaged during the axial connection of adjacent pipe sections and are so spaced axially on said couplers so that they can snap back into an overlapping locking position when said male coupler is abutted against said depression in an adjoining like chimney section.

References Cited in the file of this patent UNITED STATES PATENTS 1,308,981 Buller July 8, 1919 

1. A PREFABRICATED DOUBLE WALLED CHIMNEY SECTION ADAPTED TO BE COUPLED TO A SIMILAR SECTION TO FORM A CHIMNEY COLUMN, SAID SECTION COMPRISING: (A) AN INNER PIPE; (B) AN OUTER PIPE; (C) INSULATION BETWEEN SAID PIPES; (D) A MALE COUPLER ON THE UPPER END, AND A FEMALE COUPLER ON THE LOWER END OF SAID SECTION, SAID COUPLERS COMPRISING (E) ANNULAR RADIAL PLATES WITH INNER AND OUTER GENERALLY AXIALLY EXTENDING FLANGES CONNECTED TO SAID INNER AND OUTER PIPES FOR RETAINING THE SPACING BETWEEN THEM; (F) SAID INNER AND OUTER FLANGES OF SAID MALE COUPLER BEING RIGIDLY CONNECTED TO THE UPPER ENDS OF SAID INNER AND OUTER PIPES, RESPECTIVELY; (G) SAID OUTER PIPE BEING RIGIDLY CONNECTED TO SAID FEMALE COUPLER OUTER FLANGE AT ITS LOWER END, AND SAID INNER PIPE EXTENDING CLOSELY ADJACENT NEAR ITS LOWER END TO SAID FEMALE COUPLER INNER FLANGE AND BEING MOVABLE RELATIVE THERETO, SAID INNER PIPES OF SUCCEEDING SECTIONS EXTENDING DOWN INTO THE INNER PIPE OF THE NEXT LOWER SECTION AND BELOW SAID PLATE; (H) MEANS FOR SPACING SAID PLATES OF ADJACENT COUPLERS APART BY A PREDETERMINED AMOUNT TO PROVIDE A FIXED ANNULAR AIR SPACED BETWEEN ADJOINING SECTIONS; (I) AND MEANS ON SAID MALE AND FEMALE COUPLERS FOR AXIALLY LOCKING SAID SECTION TO AN ADJOINING LIKE SECTION. 